1. Field of the Invention
This invention relates to a battery changing system to change the battery of an industrial truck, such as a fork lift truck, having a battery block that can be moved by means of a roller conveyor in a horizontal direction relative to a battery compartment of the industrial truck.
2. Technical Considerations
On conventional industrial trucks having a battery block that can be pushed into or out of the battery compartment in a horizontal direction, for example in a lateral direction with respect to the industrial truck, the known art describes battery changing systems in which the floor of the battery compartment of the industrial truck is provided with a horizontal roller conveyor. To change the battery, an external roller conveyor is placed next to the industrial truck adjacent to the internal roller conveyor that is permanently installed in the industrial truck. Using these two conveyors, the battery block can be pulled all the way out of the battery compartment. The known art also describes industrial trucks in which the roller conveyor that is located on the floor of the battery compartment can be extended or folded outwardly so that the battery block can be pulled all the way out of the battery compartment using the roller conveyor that is permanently installed in the industrial truck. The battery can then be transported by means of a pallet truck, an overhead crane, or another industrial truck. Battery changing systems of these types are used on a wide variety of industrial trucks, such as counterweighted electric fork lift trucks, reach trucks, pallet trucks, or high lift stackers.
However, one disadvantage of these known battery changing systems is that a roller conveyor that is permanently installed in an industrial truck makes the industrial truck more expensive to manufacture. Furthermore, because the battery block in the battery compartment is mounted on the roller conveyor, the battery block must be secured and fixed in position during operation of the industrial truck to prevent movement of the battery block, for example to keep it from bumping into the walls of the battery compartment. In industrial trucks with a lateral opening for changing the battery, the battery block must also be secured in position to prevent it from unintentionally rolling out of position if the side wall of the battery compartment is open. This requirement to secure the battery block likewise entails additional manufacturing costs. Furthermore, a drive device, such as a drive mechanism for the roller conveyor, is necessary to move battery blocks that are too heavy to be moved manually. This, in turn, makes the industrial truck significantly more expensive to manufacture. High loads are also experienced in the vicinity of the points of contact between the rollers of the roller conveyor and the battery block on account of the heavy weight of the battery block. As a result of which, these areas are exposed to a high amount of wear. In addition, the roller conveyor that is permanently attached to the vehicle requires additional space inside the battery compartment, in particular in the vertical dimension of the battery compartment, which makes it more difficult to achieve the objective of the most compact possible dimensions of the industrial truck.
Therefore, it is an object of the invention to provide a battery changing system which makes it possible to change the battery while entailing relatively lower additional costs for the manufacture of the industrial truck.